Shader script nodes have no parameters
Blender has a few oddities, including:


Script need to be reloaded/refreshed when changed/loading via the little double-arrow button in the node block next to the filename. Use that when/if loading/changing.
If there are ANY errors or oddities in your script (at least in Blender 2.8) - this will result in your node not changing to reflect the current script it's pointing at. i.e. It won't give you an error, but when changing the node block from one script to another - it simply wont change. (Button above can help your diagnose errors)
FYI - If not shades to not actually work - make sure you are not using GPU rendering. OSL works with CPU rendering, only. In addition - make sure "open shading language" is checked below the CPU option (in the Scene property under "Render Engine").